Comprehensive assessment of carbon stocks and fluxes in a Boreal-Cordilleran forest management unit

A carbon budget model of the Canadian forest sector (CBM-CFS2), was modified to investigate past and possible future impacts of management on C sequestration in forest biomass, soils, and harvested wood products, for a forest management unit in the western Canadian Boreal-Cordilleran ecoregions. The model showed that total suppression of natural disturbances, and their replacement by harvesting for maximum sustainable yield, could lead to significant increases in ecosystem C storage (mainly in soils and wood products) over a period of 100-200 years in this region. This is primarily because the historical interval between disturbance events (primarily wildfire) is short compared with the harvest interval. The net gains in C storage, and the period over which they are sustainable, are sensitive to several key variables, including planned harvesting levels and the intensity of natural disturbances. A warmer climate could reduce total C storage as a result of greater soil decomposition, but it should not reverse the benefits attributable to management if disturbances are controlled. Extended rotation lengths increase total C storage significantly and may justify additional investment in protection.